In an existing LTE (Long Term Evolution) system, MIMO (Multiple Input Multiple Output) is a key technology of a physical layer, and is mainly a method of using multiple transmitting antennas and multiple receiving antennas for improving a system performance.
A precoding technology is a very important process of MIMO. Before precoding, the system maps data information to be sent to different layers by layer mapping at first, so that the data information is allocated to the different layers according to a certain mode, and then the system maps the data information allocated to the layers to physical antennas by the precoding technology. In this way, some necessary signal processing processes which are difficult to be implemented at a receiving end may be performed at a sending end, thereby ensuring a signal performance of a transmission process.
An existing precoding technology is actually an adaptive technology. With a change of CSI (Channel State Information), a result of precoding the data information may change correspondingly. This pre-processing technology for the data information changing in real time according to the change of the CSI may enable a UE (User Equipment) to obtain correct target data information from the changing CSI, thus precoding is a very critical technology in the MIMO of the LTE system.
However, performances and complexities of different precoding solutions are different from each other. Typical precoding solutions may be divided into two types: a linear precoding solution and a nonlinear precoding solution, and each type of a precoding solution has a suitable working scene of itself. In existing LTE protocols, an adopted precoding solution is the linear precoding solution, but in some scenes, gain provided by the linear precoding solution is too small to meet a transmission requirement of the system, thereby leading to great decrease of the system performance.